The capacity of forests to mitigate climate change depends on their ability to cope with and adapt to global change drivers, such as more frequent and more intense extreme events (e.g., droughts and heatwaves) and concomitant changes in atmospheric CO2 and reactive nitrogen and sulphur deposition. While these drivers have often been studied in isolation, their interactive effects on forest health and ecosystem functioning remains poorly understood. In the proposed session, we aim to bring together research communities working on assessing climate extremes and atmospheric deposition impacts on forests. We particularly welcome contributions linking processes at different vertical and spatial scales,e.g., ground-plot-based observations on soil and trees and their interactions, and how they relate to spatial, remotely-sensed regional/continental assessments and modelling. Moreover, we encourage contributions providing examples of interactions and synergies between forest monitoring networks (e.g., eLTER, ICP Forests and ICOS and other international monitoring networks) in integrating information at different scales to gain a holistic understanding of ecosystem functioning and how this can support forest related management, guidance and policy. Lastly, we invite contributions from novel manipulation experiments simulating realistic scenarios of variations in global change drivers and impacts on forest ecosystems. The session is organised within the framework of the CLEANFOREST COST Action (https://cleanforest.eu/).